Description

All public methods of Zend_Log should return the current instance (return $this) so a fluent usage is possible.

Sometimes its necessary to add more writers or event items at once and a fluent interface makes this nicer to implement. There should be no downside because in its current state all public methods return nothing.

Making visibility more restrictive (e.g., moving from public to protected or private; moving from protected to private)

However, changing the visibility at all actually can introduce some BC breakage. If a method is marked as private, and we change it to protected, we can cause BC breakage in the case where somebody has extended the class and overridden that method, while retaining the private visibility. In this case, they will get an E_FATAL as their method is now more restrictive than the method they're extending.

That said, they also need to override a public or protected method in the first place in order to even call the formerly private method. I would hope they have a good test suite in place. :)

I still think this is a good idea, but it's easier to call this sort of thing out in a minor release than in a maintenance release.